A025716 Index of 6^n within sequence of numbers of form 6^i*7^j.

1, 2, 4, 7, 11, 16, 22, 29, 37, 46, 56, 67, 79, 91, 104, 118, 133, 149, 166, 184, 203, 223, 244, 266, 289, 313, 337, 362, 388, 415, 443, 472, 502, 533, 565, 598, 632, 667, 702, 738, 775, 813, 852, 892, 933, 975, 1018, 1062, 1107, 1153, 1200, 1247, 1295, 1344, 1394